PIXE analysis of some medicinal plants used in cleaning teeth in southwestern Nigeria.

Sixteen medicinal plants used for cleaning teeth in southwestern Nigeria were analyzed using the particle-induced X-ray emission (PIXE) technique. These medicinal plants have other therapeutic uses, but the emphasis and main focus were on their beneficial effects on human teeth. PIXE measurements were carried out using 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padova Italy. The results showed the presence of 18 different elements at different concentrations, 2 plants had traces of gold, and none of the plants contained any toxic heavy metals. The metabolic roles of the detected elements were discussed especially as they affected the formation, growth, development, and protection of human teeth. The results of this study are presented and discussed.

Nigerian flora and its pharmaceutical potential.

The use of plants by man came about through observation of their definite effects on man and animals. Herbalists employ both physical and psychological treatments and herbal medicines can be used in powders, concoction, decoction, soup or ointment. Various plants used as anti-infective agents, antimalarials, laxatives, cardiovascular and nervous remedies, or containing proteolytic ferments, steroid sources, sweeteners, anti-tumour substances and as source for materials for dosage forms are discussed. Generally, plants useful in pharmaceutical and food industries and those with substances of general economic importance are also described.

Anti-implantation activity of the fruit of Lagenaria breviflora Robert.

The fruit of Lagenaria breviflora Robert (Adenopus breviflorus Benth) family Cucurbitaceae used by natives as an abortifacient in Nigeria, was investigated for anti-implantation activity. The ethyl acetate extract of the whole fruit and methanol extract of the seed were very toxic to rats. Using ten female virgin albino rats for each extract, the World Health Organization special protocol and doses on a moisture-free basis: 20 g/kg whole fruit methanol extract gave 60% anti-implantation activity, 2.5 g/kg fruit pulp gave 80% and 5 g/kg fruit pulp gave 100% activity while 2 g/kg seed also gave 100% activity but four of the rats died. Statistical evaluation of the data showed that the results were significant.

New constituents of Piper guineense fruit and leaf.

Fourteen compounds were isolated from the fruits and leaves of Piper guineense Schum and Thonn (Piperaceae). Two of those were regarded to be new natural compounds, N-pyrrolidyl-2,4-octadecadienamide and N-piperidyl-2,4-octadecadienamide.

GC/MS investigations of the minor constituents of Piper guineense stem.

Chemical investigations by GC/MS-analysis of stem extracts of Piper guineense resulted in the detection and identification of thirty-nine new constituents of the stem, apart from previously isolated constituents. These are isobutyl, pyrrolidyl and piperidyl amide alkaloids. Fifteen new natural products have been identified. Four of these natural products have been designated iyeremide A and B (these are pyrrolidine and piperidine analogues of pellitorine) and cycloguineense A and B, which are also piperidine analogues of cyclostachine A and B. There is a need to confirm the structures of some of these new constituents by synthesis. Apart from these amide alkaloids, many volatile oil components-monoterpenes, sesquiterpenes, terpenoids, lignans and sterols--were detected.

Three New Amides from Zanthoxylum rubescens.

ZANTHOXYLUM RUBESCENS stem bark has afforded three new unsaturated aromatic amides identified as N-methyl, N-(3,4- methylenedioxyphenylethyl),3',4-dimethoxycinnamoylamide ( 1), N-(3,4-methylenedioxyphenylethyl)-3'-4'-dimethoxycinnamoylamide ( 2), and N-(3,4-dimethoxyphenylethyl), 3',4'-methylenedioxycinnamoylamide ( 3). The structures of these TRANS-cinnamoylamides have been derived on the basis of spectral studies which have been confirmed by synthesis.

New amides from Zanthoxylum lemairie pericarps.

Two new aromatic amides were isolated from the pericarps of Zanthoxylum lemairie. The structures were elucidated by spectroscopic methods and confirmed by synthesis. A known aromatic amide, zanthosinamide, and four dibenzylbutyrol-actone lignans were isolated.

Antimicrobial constituents of the leaves of Acalypha wilkesiana and Aacalypha hispida.

An activity directed fractionation of a 50% aqueous ethanol extract of A. wilkesiana and A. hispida leaves resulted in the isolation of gallic acid, corilagin and geraniin as the compounds responsible for the observed antimicrobial activity. Quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside were also isolated from the inactive fraction of A. hispida. The structures were established by permethylation, 2D - NMR ((1)H and (13)C) and MS data.